Typically, conveyors have been installed in truck bodies to extend between the front wall and the tailgate of the dump body. With these longitudinal conveyors, materials in the dump bodies can be conveyed to the front or rear of the dump body to be dispensed. Some examples of these types of trucks are disclosed in U.S. Pat. No. 4,886,214 to Musso, Jr. et al., U.S. Pat. No. 5,310,119 to Musso, Jr. et al., and U.S. Pat. No. 5,397,172 to Musso, Jr. et al. which are herein incorporated by reference.
However, these types of trucks are not conveniently designed for certain types of side-dispensing applications, such as conveying and windrowing gravel, or other aggregate soil for filling trenches, road shoulders, or ditches or dispensing ice control material over the entire road. Some attempts have been made to construct side dispensing systems, but as explained below these systems are typically difficult and time consuming to install and/or are costly.
For example, one prior solution has been to develop a tailgate attachment which incorporates a conveyor or auger. Some examples of these tailgate attachments are disclosed in U.S. Pat. No. 2,879,910 to Johnson, U.S. Pat. No. 3,018,908 to Wilton et al., U.S. Pat. No. 3,122,251 to Sardipee, U.S. Pat. No. 3,300,068 to Tarrant, Sr., the Monroe Snow & Ice Control Eliminator, and Air-Flo's tailgate spreader which are all herein incorporated by reference. Although these tailgate attachments work, they are not convenient because they require the existing tailgate to be removed and replaced with the tailgate attachment. Since the tailgate attachments are large, bulky, and heavy, the mounting and dismounting operation is often difficult and time consuming. Additionally, the truck owner must buy the additional tailgate attachment which adds to the overall cost of the truck.
Another solution involves modifying the hopper to slope from the front panel and from the rear panel to a central point in front of the rear axle and onto two lateral conveyors, such as disclosed in U.S. Pat. No. 3,498,486 to Freeman, Jr. which is herein incorporated by reference. Although this modification also works for side dispensing applications, it is designed for "hopper-type" vehicles, not dump trucks which have a conventional lift cylinder that can raise one end of the dump body. Since the hopper vehicles do not have a lift cylinder, they cannot raise the hopper to direct material in the hopper towards the conveyors and thus need the sloped panels to redirect the materials. The sloped panels substantially reduce the size of the load which the hopper can carry and require the hopper body to be redesigned which is costly.
Yet another solution, involves a hopper trailer with a two-piece body where the rear body section can be tilted up towards the front of the trailer towards the front body section with a cross conveyor, such as disclosed in U.S. Pat. No. 2,534,558 to Ottenbacher which is herein incorporated by reference. Again, this solution works, but requires a complicated and costly two-piece body design with a two-piece bottom structure to shift the contents of the hopper trailer towards the front. Additionally, it requires the relocation of the lift cylinder to the rear of hopper trailer.